    document.documentElement.addEventListener(
        "touchstart",
        function(event) {
          if (event.touches.length > 1) {
            event.preventDefault();
          }
        },
        false
      );

      var lastTouchEnd = 0;
      document.documentElement.addEventListener(
        "touchend",
        function(event) {
          var now = Date.now();
          if (now - lastTouchEnd <= 300) {
            event.preventDefault();
          }
          lastTouchEnd = now;
        },
        false
      );

      document.addEventListener("gesturestart", function(event) {
        event.preventDefault();
      });